The invention is based on a magnetic valve having at least one, preferably cylindrical, soft-iron core surrounded by a coil and with an armature of magnetically conductive material, which carries a valve body, and further having a permanent magnet for reinforcing the armature movement.
A magnetic valve is known from British Pat. No. 1,490,033, the valve body of which is embodied as a ball of magnetically conductive material. A bar magnet which is magnetized in the longitudinal direction is disposed above the ball. The bar magnet is surrounded by a body of nonmagnetic material. Above the nonmagnetic body, there is a magnetic core, which is disposed coaxially with the bar magnet and surrounded by a coil. If the coil receives no electrical signals, then the ball is attracted by the bar magnet, which has different poles on its two ends, and thus remains in contact with the bar magnet. At the same time, the core is magnetized, so that the core and the bar magnet attract one another and the bar magnet strikes against the nonmagnetic body, which is located partially between the core and the bar magnet; the valve is thus in the opened state. If the coil experiences a flow of electrical current through it, a magnetic field is established in the core, causing a reversal of the magnetic poles of the core and causing the bar magnet with the ball to be repelled by the core. The ball is pressed against the valve seat, so that the valve is closed. This arrangement has the disadvantage that the advantages of the permanent-field excitation are not exploited, since the energy of the magnetic field, which takes part in the transformation of energy, encompasses only a very small part of the field energy. Among other reasons, this is because the useful magnetic field appears substantially in a magnetic circuit over large sections of which there is high magnetic resistance.